Performance Study Of Evaporative Cooling Type Heat Pipe Combined Vapor Compression Air-conditioning System

With the increase of global warming gradually and the improvement of people's living standard,the production of room air conditioners rose sharply and energy consumption became more and more serious.In this thesis,the room air conditioner was selected to study its energy consumption level and the development situation at home and abroad.On the basis of the existing energy saving technology and the construction principle of air-conditioning system,the evaporative cooling type heat pipe combined vapor compression air-conditioning system(Hereinafter evaporative cooling combined air-conditioning system for short)was proposed,which was comprised of evaporative cooling technology,separate type heat pipe technology and vapor compression refrigeration technology.A research on the system was carried out,which encompassed several major topics as follows:Firstly,the evaporative cooling combined air-conditioning system was constructed,comparing with the traditional room air-conditioning system,to analyze the energy-saving principle of the system qualitatively.DeST was used to simulate the hourly load of the room,which was accorded to determine the design condition.Moreover,based on the evaporative cooling vapor compression refrigeration mode,the main parts of evaporative cooling combined air-conditioning system were designed.Since the combined air-conditioning system can also realize evaporative cooling heat pipe mode,and in order to ensure the optimal energy saving and economy of the combined air-conditioning system under the basic cooling demand,the optimizational mathematical model with lumped parameter method was established,so as to determine the optimal heat transfer areas of evaporator and condenser with economic factors.Secondly,the mathematical models for the main components of the combined air-conditioning system were established.The steady state distribution parameter models were built for air cooling evaporator and direct evaporative cooling condenser.For the scroll compressor and the thermal expansion valve,the lumped parameter models were established.In addition,the mathematical models of the combined air-conditioning system in two refrigeration modes were constructed,and were solved with discrete method.At the same time,according to the design results of the system,the combined air-conditioning system performance test experiment table was built.The performance of different refrigeration modes with the varied dry bulb temperature of outdoor air was analyzed to verify the reliability of the model by comparison with the simulation results.Finally,based on the mathematical models of each components and their coupling relationship,the dynamic mathematical model for the combined air-conditioning system was built and solved during the cold period.Taking Shenyang area as an example,an analog simulation was carried out.Comparing with the traditional air-conditioning system and evaporative cooling vapor compression air-conditioning system(without separate type heat pipe technology),energy saving of the combined air-conditioning system can be analyzed.Moreover,analog simulations for dynamical operating functions of the combined air-conditioning system in several typical climatic conditions(e.g.Shenyang,Beijing,Changsha,Guangzhou)in China were carried out to investigate the applicability of the combined air-conditioning system.The evaporative cooling air-conditioning system took fully account of characteristics of the indoor load and the outdoor cold source,and made full use of the natural cold source on the foundation of reliable operation.By the qualitatively analysis,the results of the analog simulations and experimental study,it was shown that the combined air-conditioning system could not only guarantee the reliability of cooling,but also have economic and energy saving benefit.